Treatment of gas distribution systems



UNITED STATES PATENT. OFFICE TREATMENT OF GAS DISTRIBUTION SYSTEMS John R. Skeen, Philadelphia, Pa., assignor to The United Gas Improvement Company, a corporation of Pennsylvania No Drawing. Application March 1, 1937,

Serial No. 128,556

8 Claims. (Cl. 48190) Gas distribution systems include joints of various kinds which are packed with hemp, jute or othercellulosic fibrous absorbent material TABLE 2 Glycol derivatives causing negligible swelling which in turn is backed up with lead or cement. Per cent The transmission of dry gas through the mains Mono butyl' ether of diethylene glycol 0 causes such joints to leak for the reason that Mono phenyl ether of ethylene glycol 0 the gas absorbs moisture from the fibrous Triethylene glycol 1 p Mono .ethyl ether of triethylene glycol 2 Ethylene glycol or diethylene glycol, if success- Mono methyl amyl ether of ethylene glycol... 4 fully applied to the packing, oppose and in fact correct such gas leakage as described and claimed TABLE 3 in copending application Serial Number 673,618, filed May 31, 1933, by Duncan B. Williams and which has matured into Patent 2,094,691, Oct.

Miscellaneous materials causing negligible or incomplete swelling 5, 1937. For instance, diethylene glycol has been Per cent flowed along the bottom of the main into contact Mixed t ses 0. with the bottoms of successive joints and has Hexone 3 been found to impregnate the packing by climb- Quinoline 4 ing through it by capillary action. It has also Octyl aldehyde 8 been proposed to spray these materials into the Decane 8 main or to fog them into thegas stream. Triethyl benzene 9 Diethylene glycol and ethylene glycol are efiec Octyl l h l 11 tlve as materials for leak proofing cellulosic olive n 13 packing principally because they have the power Spindle 11 14 to swell the fibers to the same degree as has water, thereby completely restoring the desiccated packing to the expanded state in which it' was before its loss of moisture to dry gas.

Very few other substances have this ability to swell dry jute or other cellulosic fiber to substantially the same extent as does water. This ability is a unique and unpredictable property as many glycol derivatives and other apparently analogous substances do not possess it.

Water has the power .to expand the volume of dry jute fiber 44% on saturation. Water, of course, is not' available for leak proofing packing becauseof its high vapor pressure and its consequent rapid absorption by dry gas. It was this loss of water from the packing to the gas which caused the leakage it is desired to correct.

The swelling properties of various liquids are set forth in the following tables.

All of .the substances in Table 1 have low vapor pressures, are relatively inert to the gas and all of them exceptglycerine have moderate viscosities and are rapidly absorbed by the packing. .All of. them except glycerine when used by itself are very suitable for leak proofing fiber packing and are very effective when they are brought into proper contact with the packing. Glycerine by itself has too high a viscosity for rapid absorption by the packing even if brought into effective contact with it. I

In. many distribution systems, however. tar, gums, resins and dust have been deposited from the gas uponthe packing and operate to exclude packing. These substances are not effective softening agents for the tars,. gums and resins and are capable of improvement in dust wetting. 7 power though the mono methyl ethers are im- TAB'LE 1 provements over the corresponding glycols in this respect. Substances causing substantially the same The result is that in such systems the efficiency swelling as water 44% of these substances in the prevention of leakage is impaired.

06ml An object of the present invention is to pro- Ethylene glycol 44 videan improved leak proofing composition for Diethylene glycol", 44 cellulosic fiber packing in the joints of gas dis- Mono methyl ether of ethylene glycol 38 tribution systems which will possess sufiicient Mono methyl ether of diethylene glycol Glycerine solvent power in respect to tars, resins and gums the substances in Table l from-contact with the of. appropriate viscosity and vapor pressure to be readily absorbed and. retained by the packing and of suflicient swelling power to restore the desiccated fibersubstantially to its former volume 5 when it was saturated with water.

Another object of the invention is to provide an improved composition for wetting and laying dust on the walls of mains produced by the drying outof the mains by dry gas.

Generally stated this invention is an improvement in leak proofing and dust laying composi-. tions for gas distribution systems comprising two or more mutually miscible liquids, one of which is adapted to assist in softening tarry and resinous deposits which may cover joints and to increase the wettingand spreading power of the composition upon the walls of the gas mains, and is selected from the phenols such as phenol and cresol; and the other of which is adapted to cause swelling or expansion of the fiber packings to substantially the same extent as saturation with 'water. That is, the second liquid has the power to cause dry jute iiber to increase in volume in excess of say 35%, and. comprises any one or a 5 mixture of any two or more of the aliphatic polyalcohols and ethers enumerated in Table 1, namely, ethylene glycol, diethylene glycol, mono methyl ether of ethylene glycol, mono methyl ether of diethlene glycol, and glycerine.

cresol or mixtures of these in amounts u to say 40% of these aliphat c polyalcohols and ethers. facilitates the wetting and penetrating power of r the mixture with respect to the gums, tars and dust which may be present in the main and thereby facilitates the penetration of the polyalcohols and ethers to the packing within the joint. I have further found that phenol and cresol in the admixture do not reduce the powers f the other ingredients to cause swelling of the fibrous packing given in Table 1. Larger quantities of tar and gum solvent and wetting agent may be employed'if desired.

Because solutions conta ning phenol and cresol 4,5 have a sli htly more corrosiveact on upon iron than the aliphatic polyalcohols and eth'ers specified it is desirable to add from .5 to 1.5% of triwethanolamine or other suitable substance as an inhibitor of corrosion. The addition of 1.5% renders the composition containing phenol or cresol'even less corrosive than glycol or glycerine compositions in which no phenol or cresol has been included. q

An example of a preferred composition for leak "proofing and laving dust in gas distribution systems is the following: A

- Per cent Diethylene glycol Glycerine 13.5

60 Phenol. 15 Cresol 5 Triethanolamine 1.5

I As before stated, glycerine by reason of its high 35 viscosity is not readily absorbed by the packing by volume. Since cresol is not miscible with h h concentrations of lycerine it isnot interchangeable with phenol for use in leak proofing comp sitions in which the whole swelling agent consists I have found that the'addition of phenol and An example glycol. and glycerine and at least one ofa group of glycerine- However, where glycerine is mixed with a substantial percentage of the other specifled polyalcohols or ethers, cresol may be used interchangeably with phenol as thetar and gum solvent and wetting agent.

It will be seen that'in the case of the glycerinephenol composition the phenol serves a double purpose, namely (1) to reduce the viscosity of the glycerine so that rapid absorption by the jute packing is possible, and (2) to soften the tar and gum deposits and to increase the wetting action of the mixture upon dust deposits within the distribution system. -The term. phenol includes the technical and commercial grades of phenol. The same applies to the term cresol.

It will be understood that changes, omissions, additions, substitutions and/or modifications might be made within the scope of the claims without departing from the spirit of the invention.

I claim:

1. A method for treating the interior of a gas distribution system which comprises applying to the interior of said system a liquid mixture comprising a phenol and at least one of a group consisting of ethylene glycol, diethylene glycol,

monomethyl ether of ethylene glycol, monomethyl ether of diethylene glycol, and glycerine.

ene glycol, and glycerine and at least one of a group consisting of phenol and cresol.

3. A method for reducing gas leakage through fibrous packing such as jute in a joint of a gas distribution system, said packing having accumulations such as tar and gum on the surface thereof, comprising impregnating said packing with a cellulosic fiber swelling agent selected from a group consisting of ethylene glycol, diethylene glycol, monomethyl ether of ethylene glycol, monomethyl ether of diethylene glycol, and glycerine by bringing said agent into contact with said packing in the presence of a phenol, said phenol acting as a tar and gum solvet and wetting agent.

4. A method a gas distribution system, said interior aving dust sources with deposits of tar and gum thereon, comprising enveloping said dust sourceswith a dust laying liquid selected from a groupconsisting of ethylene glycol, diethylene glycol. monomethyl ether of ethylene glycol, monomethyl ether of diethylene glycol, and glycerine by bringing said liquid into contact with said dust sources in the presence of a phenol, said phenol acting as a tar and gum solvent and.wetting agent.

5. A method for rejuvenating cellulosic packing such as jute in a joint'of a gas distribution system to reduce gas leakage at said joint, said packing being at least partially coated with accumulat ons such as tar and gum. comprising contacting said packing with a liquid mixture comprising at least one of a group consisting of ethylene glycol. diethylene glycol, mono-methyl ether of ethylene glycol, mono-methyl ether of diethylene consisting of phenol and cresol.

6. A method for laying dust in a gas distribution system, the walls of said system having accumulations such as tar and gum, comprising coating the walls of said system with a liquid for laying dust in the interior of r mixture comprising at least one of a group con-= sisting of ethylene glycol, diethylene glycol, mono-methyl ether of ethylene glycol, monomethyl ether of diethylene glycol and glycerine and at least one of a group consisting of phenol and cresol.

7. In a method for reducing gas leakage through fibrous packing such as jute in a, joint of a gas conduit, the step of impregnating said fibrous packingwhile in place in said joint with a liquid mixture comprising one of a group consisting of ethylene glycol, diethylene glycol, monomethyl ether of ethylene glycol, mono-methyl ether of diethylene glycol, and glycerine and one of a group consisting of phenol and cresol.

8. A joint a gas distribution system comprising spaced cooperating elements, cellulosic fibrous packing such as jute between said cooperating elements positioned to form a seal, and a liquid mixture absorbed by said packing, said liquid mixture comprising at least one of a group con-x sisting of ethylene glycol, diethylene glycol, mono-methyl ether of ethylene glycol, monomethyl ether of diethylene glycol and glycerine and at least one of a group consisting of phenol and cresol.

JOHN R. SKEEN. 

